/*
 *  Copyright (c) 2019 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

#ifndef MODULES_AUDIO_PROCESSING_NS_NS_FFT_H_
#define MODULES_AUDIO_PROCESSING_NS_NS_FFT_H_

#include <vector>

#include "array_view.h"
#include "ns_common.h"

namespace webrtc {

// Wrapper class providing 256 point FFT functionality.
    class NrFft {
    public:
        NrFft();

        NrFft(const NrFft &) = delete;

        NrFft &operator=(const NrFft &) = delete;

        // Transforms the signal from time to frequency domain.
        void Fft(rtc::ArrayView<float, kFftSize> time_data,
                 rtc::ArrayView<float, kFftSize> real,
                 rtc::ArrayView<float, kFftSize> imag);

        // Transforms the signal from frequency to time domain.
        void Ifft(rtc::ArrayView<const float> real,
                  rtc::ArrayView<const float> imag,
                  rtc::ArrayView<float> time_data);

    private:
        std::vector<size_t> bit_reversal_state_;
        std::vector<float> tables_;
    };

}  // namespace webrtc

#endif  // MODULES_AUDIO_PROCESSING_NS_NS_FFT_H_
